Titanium implants are being implanted for terms from one to two years in Rhesus monkeys. The implants are cylindrical with a porous exterior, and are given periodic clinical evaluations as well as histological examination after term. BIBLIOGRAPHIC REFERENCE: "Effect of Loading on the Pore Structure of Low Modulus Porous Implant Materials", by M. Spector, R.A. Draughn, B.W. Sauer, and F.A. Young, IADR Programs and Abstracts, March, 1976.